In a liquid crystal display, a LED light bar is usually used as a light source, since each LED in the LED light bar is a point light source, light beams may not travel to a corner of a light incident side of a light-guiding plate, resulting in a dark corner.
In addition, when light beams of the LED light bar are emitted onto the light-guiding plate, a refraction and a reflection will occur at the light incident side of the light-guiding plate, and the refracted light beams enter into the light-guiding plate and are utilized, while most of the reflected light beams may not be utilized, therefore there is a problem of a low utilization of light beams.